Eccentric drives, particularly for sewing machines



June 18, 1957 sso I 2,795,968

ECCENTRIC DRIVES, PARTICULARLY FOR SEWING MACHINES Filed May 8, 1952 I 5Sheets-Sheet 1 FIGS In vnfo/ AZZan H. Efilksqorz y I W A Hw- June 18,1957 A. H. ERIKSSON 2,795,958

ECCENTRIC DRIVES, PARTICULARLY FOR SEWING MACHINES S Sheets-Sheet 2Filed May 8, 1952 Jun 1957 A. H. ERIKSSON ECCENTRIC DRIVES, PARTICULARLYFOR SEWING MACHINES Filed May 8, 1952 3 sh ets-sheei a MVE/VTOI? All/MH. ER/KSSON United States FatentQ ECCENTRIC DRIVES, PARTICULARLY'FORSEWING MACHINES Allan Herman Eriksson, Huskvarna, Sweden, assignortoHusqvarna V'apenfabriks Aktiebolag, Huskvarna, Sweden, *a'c'orporation'of Sweden Application May 8, 1952, Serial No. 286,772

Claims priority, application Sweden September 13, 1951 11 Claims. (Cl.74-571) The present invention refers to'eccentric drives adapted tofacilitate an accurate adjustment in the transmission of motion from arotating shaft by means of an eccentric to a reciprocating member. Thedriving means in consideration is particularly intended for sewingmachines but can be generally used in such cases where a rotary motionis to be transformed into a reciprocating motionv through theintermediary of an eccentric.

For the purpose of changing the eccentricity of an eccentric drivingdevice it is known to arrange an eccentric to be radially displaceableon the shaft, rigidly interconnected wedge members or the like beingused for this purpose, which are adapted to be adjusted axially so as tocause said radial displacement of the eccentric. An accurate adjustmentof the eccentricity supposes in such case that the wedges fit exactly inthe corresponding wedge seats of the eccentric. As a result, theadjustment of the wedges hasrequired a considerable force and also afine and expensive accuracy in manufacture.

One object of the invention is to obviate said drawback. A furtherobject is to provide an eccentric drive of the type in consideration,wherein an accurateadjustment of the eccentricity is made possible.

The substantial distinguishing feature of the invention resides,aboveall, in that the wedge members or the like have individually alimited mutual mobility in the axial direction while being resilientlyactuated in the wedging directions. he mutual mobility of the wedgemembers provides for facilities in varying the distance between thewedge surfaces of the wedge members and the corresponding wedge seats ofthe eccentric at the displacement of the latter to alter theeccentricity. In shifting, an incidental reduction of this distance maythus be obtained initially, so that the wedge members can readily slideon the corresponding surfaces of the eccentric. Spring actuation of thewedge members involves that the incidental play is nullified anew, sothat the eccentric will be safely retained in its position after anadjustment.

Further features characteristic of the invention will apppear from thefollowing description of a form of embodirnent illustrated in theaccompanying drawings.

Fig. 1 shows the eccentric drive in axial section.

Fig. 2 shows a corresponding radial section on line II II in Fig. 1.

Fig. 3 shows a corresponding horizontal projection.

Fig. 4 shows an endwise view of an eccentric slide.

Figs. 5 and 6 show two projections of a spring for the actuation. of thewedge members, said projections being taken at right anglesto eachother.

Fig. 7' illustrates the application of the invention to :a sewingmachine and shows a vertical section through the machine.

Fig. Sshows a hor'montal projection'of a detail of'the machine:according to Fig. 7.

Fig. 9 shows a transverse section on'the broken line IX-IX in Fig. 7 andFig. 9a an axial section of apart'of Fig. 9 on an en larged scale.

2,795,968 Patented June 18, 1957 Fig. 10 shows a transverse section online X-X in Fig. 7.

In Figs. 1-3 of the drawings, 10 designates a rotary shaft, whichcarries an eccentric disk 14 adapted to be peripherally adjusted and tobe secured to said shaft by meansof a screw 12, said eccentric diskpermitting of being locked by means of said screw in any suitableangular position on the shaft. The eccentric disk 14 is pro vided with aradial groove 16 in the one lateral surface thereof, said groovereceiving an eccentric slide 18 to bedisplaceably guided therein. Theeccentric .slide is formed with an eccentric 20 surrounded by aneccentric strap 22 on an eccentric rod 24. Theeccentric 20 has bearingsurfaces for slidable engagement with the disk 14. preferably at oneside only. A plate 26 secured to the free end surface. of the eccentric20 keeps the eccentric strap in position on the eccentric against anabutment 28, on theeccentric slide 18, which in turn is retained in theguiding groove of the eccentric disk by means of arcuateiguide bars 30secured .to the eccentric disk by means of screws 32.

The eccentric slide 18 is provided with mutually parallel guide surfaces34, 36 extending obliquely to the shaft 10, said guide surfaces beingadapted to guide wedge members 38, 40 displaceable on the shaft andfitting 'displ'aceably into grooves 42, 44, said grooves formingrecesses in the slide 18 at the passage opening of the latter'for theshaft 19 '(Fig. 3). The wedge members 38, 40 are actuated by springs 46which preferably take the form of leaf springs of the configurationshown in Figs. 5 and 6. These -springs are secured to the left endsurface of the wedge member 40 in Fig. l and press with their-free end,which is bent outwardly in an unloaded condition, against thecorresponding end surface of the wedge member 38. The wedge angle of thewedge members may preferably be selected so as to make the wedge membersself-locking in combination with the springs 46, so that the wedgemembers will not be unintentionally displaced under the influence of theforces in the eccentric rod 24.

The wedge members 38, 40 may be displaced along the shaft by means of anoperating member in the form of a sleeve 48 having a pair of radialflanges 50 limiting a circumferentially extending groove and anattachment 52 for acarrier 54, said attachment being formed on theone-end surface of said sleeve and projecting laterally of the shaft(behind the same). The carrier 54 may be adjustably arranged on theattachment 52, for instance by means of screws 51 threaded into thecarrier 54 and extendingthrough apertures 53 provided in the attachment,said apertures having a diameter larger than that of the stems ofthescrews. The carrier is provided with pins 56, 58 extending in thetransverse direction of the shaft and engaging recesses 60, 62 in thewedge members 38 and 40 respectively. The diameter of the pins is'smaller'than the distance between the lateral surfaces of the recesses60, 62 intended for cooperation with the pins, so that a slight play isprovided between the pins and said surfaces. If the shaft 10 rotates,the whole drive including the operating sleeve 48 will be carried alongin the movement, the wedge member 40 being preferably provided with apin 64 for a rotary movement of said sleeve, said pin-64 bearing againstthe pin 58 on the carrier 54 duringthe rotary movement. The mode ofoperation of theeccentric drive as described is broadly as follows:

Fig. 1 shows the device with the eccentric slide in a middle position.corresponding to the eccentricity naught. If'the operatin-g sleeve 48 isdisplaced to the right in Fig. 1 (the direction of the arrow 66), thewedgememb'ers 38, 40.will:be carried-along in-the movement by meansofithe carrier 54'sozaszto be displaced through 3 the cooperationbetween the wedge surfaces thereof and the oblique surfaces 34, 36, thedisplacement taking place axially into the grooves 42, 44, so that theeccentric shde .18 will be displaced radially in the groove 16 from thezero position to a position corresponding to a certain eccentricity.Displacement of the operating sleeve 48 and the wedge members in theother direction from the middle position by the same distance as beforebrings about the same eccentricity of the motion, but the radius of theeccentric will now be reversed by 180 in comparison with the formercase.

The displacement of the wedge members 38-40 takes place with the aid ofthe springs 46. At the displacement to the right (the arrow 66) the pin58 bears on the right hand side of the recess 62 in the wedge member 40,there being a certain play S between said pin 58 and the other side ofthe recess 62. When the wedge member 40 is displaced under the action ofthe pin 58, it carries the wedge member 38 along with it by means of thesprings 46 hearing on the left end surface of the wedge member 38. Thesprings 46 tend to keep the wedge member pressed toward the right so farthat the left lateral surface of the recess 60 bears on the pin 56 whilea play S is provided between the pin 56 and the opposite, that is to saythe right-hand lateral surface of the same recess. Should the Wedgemember 38 meet with so great a resistance that the springs 46 are unableto displace the wedge member 38, the pin 56 strikes against the righthand lateral surface of the wedge recess so as to positively carry thewedge member 38 along with it.

The cycle of operations will be analogous to the cycle described abovewhen the operating sleeve is displaced to the left.

The mobility of the wedge members relatively to the carrier under thespring action as described involves that a play between the wedgemembers and the wedge surfaces 34, 36 in the eccentric slide 18 isentirely eliminated and that the displacement of the wedge members isfacilitated, inasmuch as jamming of the wedge members in the wedgegrooves is avoided. It is to be noted that the wedge members upon adisplacement for the purpose of altering the eccentricity generallyadjust them selves so that there will be a play between each pin and thecorresponding lateral surfaces in the two wedge members. Only herebywill every play be eliminated between the wedge members and theeccentric slide.

in applying the invention to zigzag sewing machines, the means describedmay be used for the longitudinal movement of the feed dog and/or thelateral oscillatory movement of the needle bar, particularly if it besupple mented in the manner to be described hereinafter:

In the longitudinal vertical section through the sewing machine providedwith two eccentric drives according to the invention as illustrated inFig. 7, the same reference numerals have been used as in Figs. 1 and 2for corresponding parts. Here, the shaft constitutes the arm shaft ofthe sewing machine and thus drives the needle rod 68 of the sewingmachine. The eccentric and the eccentric rod 24 are adapted to drive thefeeding mechanism of the sewing machine to bring about the longitudinalmovement thereof. For the vertical movement of the feeder an eccentric72 is formed on a hub portion 70 of the eccentric disk 14, saideccentric 72 being surrounded by an eccentric strap 74 on an eccentricrod 76. The longitudinal movement of the feeder must permit of beingeasily varied to provide for different lengths of the stitches and fordifierent feeding directions, and this is facilitated by one of theeccentric drives.

An operating device is provided for the adjustment of the operatingsleeve 48 displaceable on the arm shaft 10 and thus of the wedge membersfor the purpose of varying the eccentricity of the eccentric drive, saidoperating device consisting of an arm 78, which is swingably mounted ona pin'80 (Fig. 8) on the inside of the .machine housing 82 while beingprovided with a pin 84 which carries a ball bearing 86 engaging betweenthe flanges 50 of the operating sleeve as shown in Fig. 7. The arm 78 isconnected by a link 88 to a crank arm 90, which is splined onto a shaft92 in a bearing 94 formed on the wall of the machine housing, and isprovided with an operating lever 96 on the outside of said wall. The arm78 is formed with two curved surfaces 98, 100, the arcuate contours ofwhich converge at a point 102, the radial distance of which from thecenter of rotation (the pin is smaller than that of any other points ofthe curved surfaces. A manually adjustable abutment, preferably in theform of a regulating screw 104 fitted into a nut sleeve 106 secured inthe wall 82 of the machine housing, is adapted to cooperate with thecurved surfaces, so that the arm 78 is permitted at operation forwardsand backwards to take angular positions corresponding to the desiredlength of the stitches, in accordance with the distance to which thescrew 104 is screwed into the nut sleeve 106. The screw carries amanipulating knob 108 secured thereto for the operation thereof. Theposition shown with the screw at the point 102 corresponds to the zeroposition of the eccentric, that is to say to the stitch length naught.If the screw 104 is screwed out, the arm 78 may be swung in the one orthe other direction through an angle, the magnitude of which isdependent on the position of the screw. A stop pin 110 secured in thenut sleeve 106 and extending inwardly toward the screw between twoshoulders 112 thereon serves to limit the movement of the screw, so thatthe curves cannot be swung entirely past the inner end of the screw.

To facilitate operation, a spring 114 may be stretched between a lug 116on the wall of the machine housing and a pin 118, for example, on thecrank arm 90, in a manner such that it will move the link 88 to theright in Fig. 8 in order thus to set the curved surface 98 against theinner end of the screw when the latter is screwed out.

.To adjust the mechanism so that the curved surface 100 will instead beset against the screw, it will be necessary ,to swing the crank arm in aclockwise direction by the eccentric and the zero position of thecontrol curve (98,

) determined by the set screw 104, it might become necessary in mountingto work the curved surfaces. This fitting work, which is frequentlytroublesome, may be avoided by forming the curved surfaces on a specialmember 105, which is preferably pivoted about the hearing pin 80, saidmember being locked to the arm 78, for instance by means of a screw 107threaded into the arm 78 and extending through a slit 109 in the curvedmember 105. The member 105 may then be adjusted into its proper positionby a small turning adjustment relatively to the arm 78, whereuponlocking may be effected by means of the screw 107.

The movements of the eccentric rods 24 and 76 can be transferred to thefeed mechanism of the sewing machine in any suitable manner. In Figs. 9and 10 the lower end of the eccentric rod 24 is journalled in a cranklever 120 on a longitudinal axis 122 which adjacent to the feed lever124 is provided with a second crank lever 126 adjustably attached to theshaft and having the feed lever 124 pivotally connected therewith.Reciprocat-ion of the crank lever 120 by the eccentric rod 24 causesreciprocating turning movements of the shaft 122 so that the crank lever126 obtains a corresponding oscillatory movement and the feed lever 124a corresponding reciprocating movement horizontally. The lower end ofthe eccentric rod 76 is journalled on a crank lever 128 keyed to alongitudinal shaft 130 which carries a crank lever 132 adjustablyclamped thereto. Said crank lever has a pin 134, which engages a guide136 formed in the feed lever 124. The eccentric rod 76 imparts anoscillatory movement to the crank lever 128 and thus to the crank lever132, whereby the pin 134 will reciprocate vertically and thereby impartthe vertical movement to the feed dog.

The manual measures for the control of the feeding and thus of thelength of the stitches will be very simple with the arrangementdescribed, inasmuch as substantially only the regulating screw 104requires to be screwed in or out into a position corresponding to thedesired stitch length. The spring 114- then keeps the curved surface 98set against the end of the screw, and in accordance with the movement ofthe screw the curved arm is then swung in a manner such that the curvedsurface '93 slides on the end of the screw. At the same time theoperating sleeve 48 is moved to the right in Fig. 7 with the aid of thearm 78 and the ball bearing 86 under the influence of the spring power,the wedge members 38, 40 being thus displaced in the same direction inthe manner hereinbefore described, so that the eccentric 20 is caused tomove radially upwards in Fig. 7 to increase the eccentricity. The crankmovement of the eccentric rod 24 is then actuated so that the feedingmechanism provides for an increased stitch length. If it is desiredinstead to operate backwards and to maintain the adjusted stitch length,it is only necessary to press the operating lever 96 against the actionof the spring 114 so that the arm 78 is swung in a clockwise directionin Fig. 7, until the corresponding point on the curved surface 100strikes against the regulating screw 104 (the curved surfaces 98, 100are taken to be symmetrical with respect to the point 102). Theoperating sleeve 48 and the wedge members 38, 40 are then moved to theleft in Fig. 7, while the eccentric 20 is moved downwardly so as to passthe zero position. In other words, the position of the eccentric radiuswill be reversed by 180 while being of the same magnitude as before.

The eccentric drive adapted to the zigzag motion is analogous with thatpreviously described but differs structurally in several respectstherefrom, among other things depending upon the fact that in this caseno reverse of the feed direction of the driven element is required.

The eccentric drive obtains its movement by a gear wheel 201 on the armshaft 10 said gear meshing with a gear wheel 214 of a double size whichin turn is peripherally adjustably keyed by a screw 212 to a transversehollow shaft 210. This shaft has its'one end journalled in a cover 217in one wall of the machine housing 82 and its other end in a bushing 202which is keyed in a projecting portion of the opposite wall of themachine housing. An adjustable ring 203 locked to the latter shaft endretains the shaft 210 in an axially fixed position. The shaft 210presents two longitudinal diametrically opposite slots 204 for atransverse pin 254 in an operating rod 252 displaceable in the shaft210. The pin 254 can be adjusted about its shaft and be fixed in theadjusted position by a screw 251. One end 256 of the pin is eccentricand engages a transverse recess 260 in the bottom of the wedge 238, aplay (for example 0.2-0.35 mm.) being present between the sides of therecess and the pin. The other end 258 of the pin 254 which is concentricwith the main portion of the pin engages a circular bore in the wedge240 the same play being present at this end. Leaf springs 246 of thesame construction as those illustrated in Figs. 5-6 are secured to thewedge 240 by a screw 205. The pin 254 entrains the rod 252 as the shaft210 rotates.

Mounted on the gear wheel 214 analogously with the eccentric slide 18 inFigs. 1-7 is an eccentric slide 218, which carries an eccentric 220surrounded by an eccentric strap 222 having an eccentric rod 224. Theeccentric slide 218 cooperates With the wedges 238, 240 similarly to thecooperation of the slide 18 with the wedges 38, 40 illustrated in Fig.1.

For the adjustment of the wedges there is an operating mechanism which,in addition .to the above mentioned pi'n 254 and the operating rod'252,comprises a pressure spring 206 inserted in the bore of the shaft 210, aball 286 and a shaft 292 having a hand wheel 296. The operating rod 252is pressed against the ball 286 by the pressure spring 206, the ball inturn engaging an enlarged end portion 207 of the shaft 292. The shaft292 has exterior screw threads and is fitted into a screw threadedsleeve 208 which is screwed into a cover 209 attached in an aperture inthe wall of the machine housing. The cover 209 has a collar 213surrounding a flange 208a on the screw-threaded sleeve 208*andhaving astop screw 211. The screw-threaded sleeve may be keyed in an adjustedposition by tightening the stop screw 211 at the flange 208a. The collar213 has graduations, for example in the form'of a number ofcircumferential grooves 215-located along the collar and correspondingto various breadth of the zigzag seam.

The eccentric rod 224 is articulated toa known oscillatory needle barframe (Fig. 7) in which the needle bar 68 is displace'ably journalled ina known manner. The oscillatory needle bar frame 150 is journalled inthe machine head on a'horiz'ontal shaft 152 and is adapted to beoscillated on said shaft by the eccentric rod 224. Simultaneously theneedle bar 68 is reciprocated vertically by a crank mechanism known perse and substantially comprising a crank lever 154 attached to the foreend of the arm shaft 10 and a crank rod 158 journalled on a crank pin156 of said lever 154, the crank rod 158 carrying a slide block 160displaceable in a guide 162 which is engaged displaceably byacross pin164 attached to the needle bar '68-.

The eccentric drive'last described is operated for obtaining differentbreadths of the zigzag scam in the following manner:

The operating mechanism is suitably set in a zeropositioncorresponding'to straight seam, when the hand wheel 296 isentirely "extracted as in the position illustrated in Fig. 9. Theenlarged-end portion 207 of the hand wheel shaft 292 now engages theinner end of the screw-threaded sleeve 208. By rotation said sleeve 208may be adjusted so as to take a position corresponding to the zeroposition, in which itcan be locked by the set screw 211. By screwingthewheel shaft 292 inward by'rneans of the hand wheel'296, the operatingrod 252 may be displaced to the left in Fig. 9, and as a result the pin254 carries one of the wedges 238, 240 and, by wayof the springs 246,also-the other of these wedges. Simultaneously the eccentric slide 218is displaced and the eccentricity changed in the manner previouslydescribedin connection with Figs. 12 so that the eccentric rod 224-obtains a reciprocating motion, the magnitude of which is dependent uponthe adjusting position of the operating wheel. The movement istransmitted .to the oscillatory needle bar frame, which imparts acorresponding oscillation to the needle bar'68, and at the same time theneedle bar 68 obtains a vertical reciprocation by the arm shaft 10 andthe crank mechanism 154-164.

In this eccentric drive there is no need for a reverse of the directionof the eccentric radius. In sewing zigzag seam the needle bar oscillatesabout a central position corresponding to straight seam. The plays atthe end portions 256, 258 of the pin 254 in the Wedges 238, 240 can beadjusted to a suitable magnitude by rotation of the pin 254. Such anadjustment corresponds to an adjustment of the position of a carrier 54in the eccentric drive illustrated in Fig. 2.

Though the eccentric drive first described is mentioned to cooperatewith the feed mechanism it may be used also for the zigzag motion.Likewise the eccentric drive last described can be modified to beemployed for the operation of feed mechanism in sewing machines and alsofor other purposes and in other combinations than in sewing machines.

What I claim is:

1. An eccentric driving mechanism for transmitting motion of a rotaryshaft, comprising an eccentric, having wedge seats slanting to theshaft, means on the shaft for guiding said eccentric radially relativelyto the shaft, wedge members mounted axially displaceably at oppositesides of the shaft and engaging said wedge seats, the wedging directionof one of said wedge members being axially reverse to the wedgingdirection of the other wedge member, means for resilient actuation ofthe wedge members in the wedging directions, and operating means foraxial displacement of the wedge members permitting limited mutualmobility of the wedge members.

2. An eccentric driving mechanism for transmitting motion of a rotaryshaft, comprising an eccentric formed with wedge seats located obliquelyto the shaft, means on the shaft for guiding said eccentric radially tothe shaft, axially displaceable Wedge members mounted at opposite sidesof the shaft for engagement with said seats, the wedge members havingreverse wedging directions, an operating member common to the Wedgemembers for positive actuation of one of the wedge members reversely tothe wedge direction, and resilient means for transmitting the actuationof the operating member to the other of the wedge members.

3. An eccentric driving mechanism as claimed in claim 2, in which theresilient means comprises a spring attached to one of the wedge membersand engaging the other.

4. An eccentric driving mechanism as claimed in claim 2, in which theresilient means comprises a leaf spring secured to an end surface of oneof the wedge members and acting upon an end surface of the other wedgemember in its wedging direction.

5. An eccentric driving mechanism for transmitting motion of a rotaryshaft, comprising an eccentric formed with parallel wedge seatsextending obliquely to the shaft, means on the shaft to guide saideccentric radially to the shaft, axially displaceable wedge membersmounted at opposite sides of the shaft for engagement with said seats,an operating member common to both wedge members, entraining meansconnected with the operating member and engaging both wedges, an axialplay being present between engaging surfaces of the operating member andcorresponding engaging surfaces of the wedges, and means for resilientactuation of the wedge members in the Wedging directions.

6. An eccentric driving mechanism as claimed in claim 5 in which theentraining means comprise pins projecting in the transverse direction ofthe shaft, the wedges being formed with recesses for receiving saidpins.

7. An eccentric driving mechanism for transmitting motion from a rotaryshaft, comprising an eccentric formed with wedge seats one slanting toand the other slanting from the shaft, means for guiding said eccentricradially to the shaft, means to key said guiding means to the shaft tocause the eccentric to rotate with the shaft, wedge members mountedaxially displaceably at opposite sides of the shaft and engaging saidwedge seats, said wedge members having reverse wedging directions, meansfor resilient actuation of the wedge members in the wedging directions,an operating sleeve for the axial displacement of the wedge members, thewedge members being movable to a limited extent relatively to saidsleeve and to one another, and means for carrying along the sleeve inthe rotary movement of the wedge and the shaft.

8. An eccentric driving mechanism for transmitting motion from a rotaryshaft, comprising an eccentric formed with wedge seats disposedobliquely to the shaft, said eccentric having radial guide surfaces atits one side, axiallydisplaceable wedge members mounted on a cylindricalportion of the shaft for cooperation with said wedge seats, a carryingmember formed with radial guides for engagement with the radial guidesurfaces of the eccentric, said carrying member being peripherallyadjustably keyed to the shaft, operating means for axially displacingthe wedge members relatively to the eccentric to cause radial adjustmentthereof for changing the eccentricity of the drive, said operating meanscomprising resilient means for transmitting its axial operating movementfrom one wedge member to the other.

9. An eccentric driving mechanism comprising a shaft with an axial boreand slots extending from the exterior surface of the shaft to said bore,guide means attached to the shaft for rotation therewith, an eccentriccarried by said guide means and guided for radial adjustment thereon,said eccentric being formed with wedge seats disposed obliquely to theshaft, axially displaceable wedge members mounted at opposite sides ofthe shaft for engagement with said seats, said Wedge members havingradial recesses, and operating means for the axial displacement of thewedge members on the shaft to cause radial displacement of the eccentricfor changing the eccentricity of the drive, said operating meanscomprising an operating rod mounted for axial displacement in the boreof the shaft, a pin attached transversely to said rod and extending withits end portions through said slots into the recesses of the wedgemembers, play being present laterally between said recesses and said pinend portions.

10. An eccentric driving mechanism as claimed in claim 9 in which oneend portion of the transverse pin is eccentric on the pin, the pin beingmounted for rotary adjustment in said operating rod, and means beingpro- 'vided to lock the pin in its adjusted positions.

11. An eccentric driving mechanism as claimed in claim ,9 and furthercomprising a screw-threaded operating shaft, a hand wheel keyed to saidshaft for rotary adjustment thereof, a sleeve having a screw threadengaged by said shaft, said sleeve being adjustable and adapted to belocked to the machine housing for adjustment of the zero position of theoperating means.

References Cited in the file of this patent UNITED STATES PATENTS

